<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<style>
    #user{
        display: block;
    }
    #email{
        display: block;
    }
    #personal_data{
        display: block;
    }
</style>
<body>
<form action="">
    <label for="user">用户名：</label>
    <input type="text" id="user" class="required"> <br>
    <label for="email">邮箱：</label>
    <input type="email" id="email" class="required"> <br>
    <label for="personal_data">个人资料：</label>
    <input type="text" id="personal_data"> <br>
    <input type="submit" value="提交" id="submit">
    <input type="reset" value="重置">
</form>
<script src="jquery-1.12.4.js"></script>
<script>
    $(function () {
        $("form :input.required").each(function () {
            var $required = $("<strong class='high'>*</strong>")
            $required.insertAfter(this);
        })
    })
</script>
</body>
</html>





















































